From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from resqmta-ch2-07v.sys.comcast.net ([69.252.207.39]:49008 "EHLO resqmta-ch2-07v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753669AbaK0AUw (ORCPT ); Wed, 26 Nov 2014 19:20:52 -0500 Message-ID: <54766E5C.8010909@pobox.com> Date: Wed, 26 Nov 2014 16:20:44 -0800 From: Robert White MIME-Version: 1.0 To: Roman Mamedov CC: linux-btrfs@vger.kernel.org Subject: Re: Can't cp --reflink files on a Ext4-converted FS w/o checksums References: <20141127005527.42a7fe59@natsu> <54765FC2.2050309@pobox.com> <20141127043337.198d6084@natsu> In-Reply-To: <20141127043337.198d6084@natsu> Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 11/26/2014 03:33 PM, Roman Mamedov wrote: > Finished with no rewriting necessary. After that I recursively-removed the +C > attribute from all newly reflinked files, and cp --reflink as well as > snapshotting of those works fine. I did some double checking and I think you'll find that if you lsattr those files they still have the C (NoCOW) attribute, which also means they are still unsummed. Which also means that when you cp --reflink them the target files you create are also NoCOW. So you harmonized the lack of checksums with the linux-level C attribute. This has hidden your problem but not fixed it. (Trying to clear the NOCOW attribute on a file in BTRFS is _silently_ ignored as invalid. That recursive removal only changed the directories.)